Operation Manual
BX25,
RCK54(P)-23BX,
RCK60B-23BX,
LA240,
BT601,
WSM
BACKHOE
• Boom (Up)
(1
)
c:C>
3TAAAAGNP017
A
T
(2) (3) (4)
(1) Boom Cylinder
(5) Spool
P:
Pump Port
A5:
A5 Port
(2) Boom Control Valve
(6) Inlet Section
T:
Tank Port
(From Boom Cylinder)
(3) Bridge Passage
(7) Outlet Section
P.B.
:Power Beyond Port
B5:
B5 Port
(4) Load Check Valve
(To Boom Cylinder)
a:
Low Pressure
b:
High Pressure
1.
When the boom and swing lever is pulled to the backward to set to the
"UP"
position, the spool (5)
of
the boom
control valve (2) moves to the left, which forms oil passage between bridge passage (3) and B5 port, and between
A5 port and T port.
2. The pressure-fed oil from the P port opens the load check valve (4) and flows to
B5 port to retract the boom
cylinder.
3.
Return oil from the boom cylinder returns to the transmission case through the
AS
port, low pressure passage and
T port.
9-M12